全文获取类型
收费全文 | 11486篇 |
免费 | 1302篇 |
国内免费 | 70篇 |
专业分类
耳鼻咽喉 | 182篇 |
儿科学 | 331篇 |
妇产科学 | 282篇 |
基础医学 | 1316篇 |
口腔科学 | 176篇 |
临床医学 | 1118篇 |
内科学 | 2540篇 |
皮肤病学 | 341篇 |
神经病学 | 759篇 |
特种医学 | 636篇 |
外国民族医学 | 1篇 |
外科学 | 1939篇 |
综合类 | 476篇 |
一般理论 | 10篇 |
预防医学 | 735篇 |
眼科学 | 207篇 |
药学 | 747篇 |
中国医学 | 81篇 |
肿瘤学 | 981篇 |
出版年
2023年 | 94篇 |
2022年 | 133篇 |
2021年 | 371篇 |
2020年 | 274篇 |
2019年 | 363篇 |
2018年 | 392篇 |
2017年 | 315篇 |
2016年 | 365篇 |
2015年 | 413篇 |
2014年 | 488篇 |
2013年 | 529篇 |
2012年 | 707篇 |
2011年 | 767篇 |
2010年 | 478篇 |
2009年 | 356篇 |
2008年 | 566篇 |
2007年 | 589篇 |
2006年 | 595篇 |
2005年 | 510篇 |
2004年 | 486篇 |
2003年 | 432篇 |
2002年 | 387篇 |
2001年 | 280篇 |
2000年 | 295篇 |
1999年 | 278篇 |
1998年 | 113篇 |
1997年 | 106篇 |
1996年 | 82篇 |
1995年 | 79篇 |
1994年 | 86篇 |
1993年 | 75篇 |
1992年 | 171篇 |
1991年 | 170篇 |
1990年 | 173篇 |
1989年 | 150篇 |
1988年 | 170篇 |
1987年 | 139篇 |
1986年 | 131篇 |
1985年 | 106篇 |
1984年 | 75篇 |
1983年 | 66篇 |
1982年 | 41篇 |
1981年 | 29篇 |
1980年 | 32篇 |
1979年 | 41篇 |
1978年 | 35篇 |
1974年 | 29篇 |
1973年 | 31篇 |
1971年 | 27篇 |
1970年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Enterovirus 71 (EV71) is a highly infectious major causative agent of hand, foot, and mouth disease (HFMD) which could lead to severe neurological complications. There is currently no effective therapy against EV71. In this study, RNA interference (RNAi) is employed as a therapeutic approach for specific viral inhibition. Various regions of the EV71 genome were targeted for inhibition by chemically synthesized siRNAs. Transfection of rhabdomyosarcoma (RD) cells with siRNA targeting the 3'UTR, 2C, 3C, or 3D region significantly alleviated cytopathic effects of EV71. The inhibitory effect was dosage-dependent with a corresponding decrease in viral RNA, viral proteins, and plaque formations by EV71. Viral inhibition of siRNA transfected RD cells was still evident after 48 h. In addition, no significant adverse off-target silencing effects were observed. These results demonstrated the potential and feasibility for the use of siRNA as an antiviral therapy for EV71 infections. 相似文献
102.
PURPOSE: The APC I1307K and E1317Q variants predispose to colorectal adenomas and carcinomas in Caucasians, but data are lacking in Asians. METHODS AND RESULTS: We sequenced the APC gene from codons 1261 to 1409 and found none of 147 Chinese, 20 Malay, and 11 Indian colorectal cancer patients in Singapore to carry the APC I1307K or E1317Q variants. CONCLUSION: These variants are rare in these Asian populations, and play little role in colorectal cancer causation in Chinese. 相似文献
103.
Characterization of knitted polymeric scaffolds for potential use in ligament tissue engineering 总被引:4,自引:0,他引:4
Ge Z Goh JC Wang L Tan EP Lee EH 《Journal of biomaterials science. Polymer edition》2005,16(9):1179-1192
Different scaffolds have been designed for ligament tissue engineering. Knitted scaffolds of poly-L-lactic acid (PLLA) yarns and co-polymeric yarns of PLLA and poly(glycolic acid) (PLGA) were characterized in the current study. The knitted scaffolds were immersed in medium for 20 weeks, before mass loss, molecular weight, pH value change in medium were tested; changes in mechanical properties were evaluated at different time points. Results showed that the knitted scaffolds had 44% porosity. There was no significant pH value change during degradation, while there was obvious mass loss at initial 4 week, as well as smooth molecular weight drop of PLLA. PLGA degraded more quickly, while PLLA kept its integrity for at least 20 weeks. Young's modulus increased while tensile strength and strain at break decreased with degradation time; however, all of them could maintain the basic requirements for ACL reconstruction. It showed that the knitted polymeric structures could serve as potential scaffolds for tissue-engineered ligaments. 相似文献
104.
The plasminogen activation system reduces fibrosis in the lung by a hepatocyte growth factor-dependent mechanism 总被引:12,自引:0,他引:12
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hattori N Mizuno S Yoshida Y Chin K Mishima M Sisson TH Simon RH Nakamura T Miyake M 《The American journal of pathology》2004,164(3):1091-1098
Mice deficient in the plasminogen activator inhibitor-1 gene (PAI-1-/- mice) are relatively protected from developing pulmonary fibrosis from bleomycin administration. We hypothesized that one of the protective mechanisms may be the ability of the plasminogen system to enhance hepatocyte growth factor (HGF) effects, which have been reported to be anti-fibrotic in the lung. HGF is known to be sequestered in tissues by binding to extracellular matrix components. Following bleomycin administration, we found that HGF protein levels were higher in bronchoalveolar lavage fluid from PAI-1-/- mice compared to wild-type (PAI-1+/+) mice. This increase could be suppressed by administering tranexamic acid, which inhibits plasmin activity. Conversely, intratracheal instillation of urokinase into bleomycin-injured PAI-1+/+ mice to activate plasminogen caused a significant increase in HGF within bronchoalveolar lavage and caused less collagen accumulation in the lungs. Administration of an anti-HGF neutralizing antibody markedly increased collagen accumulation in the lungs of bleomycin-injured PAI-1-/- mice. These results support the hypothesis that increasing the availability of HGF, possibly by enhancing its release from extracellular matrix by a plasmin-dependent mechanism, is an important means by which activation of the plasminogen system can limit pulmonary fibrosis. 相似文献
105.
Cytokine responses in mice infected with<Emphasis Type="Italic"> Clonorchis sinensis</Emphasis> 总被引:5,自引:0,他引:5
FVB and BALB/c mice show different morbidity, development of Clonorchis sinensis, and pathological changes following C. sinensis infection. FVB mice are susceptible and BALB/c mice are relatively more resistant to C. sinensis infection. To investigate the relationship between cytokine reaction and susceptibility to C. sinensis infection in FVB and BALB/c mice, we described both the patterns and kinetics of Th1 cytokines and Th2 cytokines in spleen cell culture. Interleukin (IL)-4 and IL-10 cytokine production in the culture supernatants of the concanavalin-A-stimulated spleen cells increased at 2–3 weeks post-infection in both strains. IL-5 production increased between 2 and 5 weeks post-infection in both strains, and reached a peak level at 2 weeks post-infection in BALB/c mice and 4 weeks post-infection in FVB mice. In contrast, gamma interferon (IFN-) production decreased between 2 and 4 weeks in both strains. IL-2 production increased slightly in BALB/c mice following infection, but was unchanged in FVB mice. IL-4 production over preinfection levels was significantly higher in FVB mice, whereas IFN-, IL-2, and IL-10 production were significantly higher in BALB/c mice. The levels of serum immunoglobulin E (IgE) and blood eosinophils in both mouse strains significantly increased between 3 and 6 weeks postinfection. Serum IgE levels were significantly higher in FVB mice than in BALB/c mice. The results of this study suggest that susceptibility to C. sinensis infection is associated with Th2 cytokine production, especially IL-4 which is predominant in relatively susceptible FVB mice. 相似文献
106.
107.
Intracranial germ cell tumours are rare. The incidence of primary intracranial yolk sac tumour is even more uncommon, with only two reported cases being associated with Down's syndrome in the English literature. This report details the findings of yolk sac tumour in the pineal region affecting a 22 year old Chinese man with Down's syndrome. Histology revealed yolk sac tumour with only a solid pattern, potentially mimicking the more common germinoma in the pineal region. No other germ cell components were identified. This is the third report of intracranial yolk sac tumour manifesting in a patient with trisomy 21. The pathology of this tumour and its differential diagnoses are discussed. 相似文献
108.
The selection of T cell receptor specificities must logically not only involve the alpha beta-TCR but, also the CD4 and CD8 molecules, as antigen recognition by the alpha beta-TCR on mature T cells is facilitated by the CD4 and CD8 co-receptors. In this review, the studies that provided key advances in our understanding of the possible role of CD4 and CD8 in T cell development will be discussed. 相似文献
109.
110.
K T Goh S K Ng S Kumarapathy 《The Southeast Asian journal of tropical medicine and public health》1985,16(1):49-53
Fifty-seven (17.3%) of 330 incoming aircraft landing at Changi International Airport were found to harbour mosquitoes and other insects on board. The frequency of insects detected in aircraft from the Southeast Asian countries varied from 7.1% to 32.2%. Live insects were found in 5 (6.1%) of 82 aircraft disinsectized by the "block away" method. The species of mosquitoes brought in were: Culex quinquefasciatus (96), Culex tritaeniorhynchus (1), Aedes albopictus (2) and Aedes aegypti (1). None of the 51 female Culex quinquefasciatus dissected was found to be infected with microfilariae. They key to the prevention of introduction of exotic vectors and transmission of vector- borne diseases is to continue with the existing system of vector surveillance and control at the international airport, rather than routine disinsecting of aircraft landing in Singapore. 相似文献